﻿// Jinx AJAX Framework
// Copyright (C) 2008 Blake Hegerle
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

using System.Collections;
using System.Collections.Generic;

namespace Core
{
    public class Set<T> : ICollection<T>
    {
        private readonly Dictionary<T, object> Model;

        public Set()
        {
            Model = new Dictionary<T, object>();
        }

        public Set(IEqualityComparer<T> Comparer)
        {
            Model = new Dictionary<T, object>(Comparer);
        }

        #region ICollection<T> Members

        public void Add(T item)
        {
            Model[item] = null;
        }

        public void Clear()
        {
            Model.Clear();
        }

        public bool Contains(T item)
        {
            return Model.ContainsKey(item);
        }

        public void CopyTo(T[] array, int arrayIndex)
        {
            foreach (var i in this)
                array[arrayIndex++] = i;
        }

        public int Count
        {
            get { return Model.Count; }
        }

        public bool IsReadOnly
        {
            get { return false; }
        }

        public bool Remove(T item)
        {
            return Model.Remove(item);
        }

        public IEnumerator<T> GetEnumerator()
        {
            return Model.Keys.GetEnumerator();
        }

        IEnumerator IEnumerable.GetEnumerator()
        {
            return GetEnumerator();
        }

        #endregion

        public bool TryAdd(T item)
        {
            var OldCount = Count;

            Model[item] = null;

            return OldCount != Count;
        }
    }
}